The present article seeks to describe a major group of Jewish North-Eastern Neo-Aramaic (NENA) dialects located across the Great Zab river in the eastern and south-eastern parts of the dialectological map of NENA, hence the term “Trans-Zab Jewish Neo-Aramaic” (“Trans-Zab”, for short) chosen for this dialect group. A large set of phonological, morphophonological, morphological and lexical innovations, shared by all members of this group, is presented. Each of the Trans-Zab features is compared with contrastive parallel features in other, selected NENA varieties. Finally, an internal classification of Trans-Zab into three subdivisions is proposed, based on a comparison of three respective paradigms of the positive present copula.